下弦月

third quarter or waning moon

third quarter moon, aka last quarter moon

down / downwards / below / lower / later / next (week etc) / second (of two parts) / to decline / to go down / to arrive at (a decision, conclusion etc) / measure word to show the frequency of an action

moon / month / monthly / CL:個|个[ge4],輪|轮[lun2]

bow string / string of musical instrument / watchspring / chord (segment of curve) / hypotenuse / CL:根[gen1]

half-moon / the 7th and 8th and 22nd and 23rd of the lunar month

third quarter or waning moon

last quarter, aka third quarter (phase of the moon)